Electrooxidation Kinetics of Hydrazine on Y-type Zeolite-encapsulated Ni(II)(salen) Complex Supported on Graphite Modified Electrode

摘要

The electrocatalytic oxidation of hydrazine was investigated on the zeolite-encapsulated Ni(II)(salen)[salen: N, Nbis(salicylidene)ethylenediamine] complex supported on graphite modified glassy carbonelectrode (Ni(II)(salen)Y/GCE). The modified electrode shows efficient electrocatalytic activity foranodic oxidation of hydrazine in 1.0 M NaOH solution. Anodic peak potential of hydrazine oxidationat the surface of Ni(II)(salen)Y/GCE shifts near 100 mV toward negative position compared with thaton bare GCE. And the Ni(II)(salen)Y/GCE also significantly enhances the anodic current for catalyticoxidation of hydrazine compared with that on bare GCE, Graphite/GCE, NaY/GCE and Ni(II)Y/GCE.The kinetics of the reaction between the Ni(II)(salen) complex on the surface of modified electrodeand hydrazine was characterized using cyclic voltammetry and chronoamperometry. The diffusioncoefficient (D) and electron transfer coefficient () of hydrazine under the experimental conditionswere investigated, and the heterogeneous rate constant, kcat, for the oxidation of hydrazine at thesurface of the Ni(II)(salen)Y modified electrode was also obtained in the same time. Finally, thegeneral reaction mechanism for the electrooxidation of hydrazine on the Ni(II)(salen)Y/GCE in pH 14alkaline solutions involves a transfer of four electrons process in which the first electron transferreaction acts as the rate-limiting step followed by a 3-electron process generating environmentallyfriendly nitrogen and water as final products.